I. Field of the Invention
The present invention relates to automotive fuel filling systems.
II. Description of the Related Art
All automotive vehicles include fueling systems to allow the fuel tank for the vehicle to be refilled. Typically, the fueling system includes a funnel which is dimensioned to receive a conventional fuel filling nozzle. The funnel in turn is connected to the fuel tank for the vehicle. Many of these fuel filling systems also include an orifice inserted into or formed as a part of the funnel which is dimensioned to receive the neck of the fuel filling nozzle. A spring loaded flapper valve is also oftentimes mounted to the funnel and movable between an open and a closed position and urged towards its closed position by the spring. Upon insertion of the fuel filling nozzle into the orifice, the fuel filling nozzle contacts and moves the flapper valve to an open position to enable fueling of the vehicle.
One disadvantage of the conventional fuel filling systems for automotive vehicles is that the flapper valve which closes the funnel port is freely movable between an open and a closed position. Fuel nozzles, furthermore, have standardized diameters depending upon the type of fuel. For example, a fuel nozzle for unleaded gasoline has a first diameter while a fuel nozzle for diesel fuel has a second and larger diameter.
The size of the fuel port in the fuel funnel assembly is dimensioned for the type of fuel utilized by the engine. Consequently, since the fuel nozzle for diesel fuel has a larger diameter than the fuel nozzle for unleaded gasoline, the fuel, nozzle for diesel fuel cannot be inserted into the fuel funnel assembly for a vehicle which utilizes unleaded gasoline.
Unfortunately, the converse is not true. Instead, since the fuel nozzle for unleaded gasoline is smaller in diameter than the fuel nozzle for diesel fuel and also since the fuel flapper valve is normally freely pivotably mounted to the fuel funnel assembly, it is possible to inadvertently fuel the fuel tank of a vehicle having a diesel engine with unleaded gasoline. This, in turn, results in damage if not total destruction of the engine.
In order to prevent refueling a diesel engine fuel tank with unleaded gasoline, there have been previously known miss-fuel inhibitors (MFI) which prevent a diesel fuel tank from being filled with unleaded gasoline even though unleaded gasoline utilizes a smaller fuel filling nozzle size. One such MFI is disclosed in U.S. Pat. No. 6,968,874.
In the '874 patent, a pair of diametrically opposed latches engage and hold the flapper valve in its closed position. Each latch, furthermore, includes an actuator surface which, when physically engaged, forces the latch outwardly thus releasing the flapper valve.
With this previously known MFI, upon insertion of the larger diameter diesel fuel nozzle into the fuel filling system, the diesel fuel filling nozzle has a diameter sufficiently large so that it engages the actuator surface on both latches thus moving both latches to an open position and allowing refueling of the fuel tank with diesel fuel. Conversely, upon insertion of a smaller diameter unleaded fuel nozzle, at most, a single actuator surface on one of the latches so that the other latch will maintain the flapper valve in a closed position and prevent refilling of the diesel fuel tank with unleaded gasoline.
A further complication, however, arises with diesel fuel since diesel fuel nozzles vary in size from about 24.5 millimeters to about 32 millimeters depending upon the type of automotive vehicle. For example, commercial vehicles utilizing diesel fuel oftentimes have the larger size fuel filling nozzle whereas passenger vehicles with diesel engines typically have the smaller diameter diesel nozzles.
It would, of course, be possible to simply design an MFI for diesel fuel in which the diesel fuel nozzle pivots the latches to an open position whenever the fuel filling nozzle is greater than 24.5 millimeters in diameter. However, if the larger diameter fuel filling nozzle of 32 millimeters were inserted into the same fuel filling system, the fuel filling nozzle would pivot the latches outwardly to such an extent that the overall diameter of the fuel filling system would necessarily be increased. Such an increase in the diameter of the fuel filling system is unacceptable for many automotive applications.